Officers of Penril Corp., a Rockville manufacturer of data communications equipment, electronic instruments, power supplies and loudspeaker systems, yesterday forecast a strong economic picture despite financial gloom across the country.

At its annual meeting Penril President Kenneth Miller reported that he expects first quarter revenues to exceed $7 million, up 100 percent from the $3.4 million last year.

Last years's revenues for the company, one of the fastest-growing in the Washington area, increased 67 percent over the previous year. Profits rose 33 percent.

"In fact, our 1979 revenue increased fivefold over our revenue of only five years ago," Miller said.

"The 1979 record-breaking results extend to six consecutive years' increases in revenue, earnings and cash dividend payouts," Miller said.

Although the firm's first quarter earnings have not yet been released, Miller said, "There is no reason known to me why we should not expect another record quarter compared to the first quarter of our prior year." e

Based on preliminary figures for the first quarter, which ended Oct. 31, the company expects an annual revenue rate of $30 million. Revenues last year were $22 million.

In addition, last month the firm became a member of the American Stock Exchange and during the last 13 months made four acquisitions.

In fact, good acquisitions are a key to the firm's success, according to Miller, who delivered to the stockholders yesterday a 10-point primer on achieving good acquisitions.

Despite high interest rates Miller said that Penril will continue to shop for new acquisitions.

"While most economists agree we are in a recession, there is a lack of unified agreement on the mangitude, outlook and intensity to be expeced," Miller said. "To date we at Penril have not experienced a downturn. Bookings are reasonably good and we have a record high backlog."

"Historically, the businesses we are in, for the most part, have fared well during periods of economic turndown," Miller added.

More than 250 large corporations and government agencies use Penril products. A major product line is a communications instrument called modem, which converts digital computer language into a format for electronic transmission over telephone lines.

Penril also manufactures test instruments and working tools for engineering laboratories and factories. Epicure Products Inc., a loudspeaker producer, was purchased for $3 million in 1978.

Another acquisition, for $1.5 million, was the Variac auto transformer and line voltage regulator business of Gen Rad Inc., of Concord, Mass.